Electric gage



(No Model.) 2 Sheets-Sheet 1.

O. D. WARNER.

ELECTRIC GAGE.

N0. 309,1 14. I Patented Dec. 9, 1884.

M ii

INVENTOR W1 CiuzrZe; Z7. Wizrnen By hi8 Attorneys (No Model.) 2 Sheets-Sheet 2.

0. D. WARNER.

ELECTRIC GAGE.

' Patented Dec. 9, 1884.

WITNESSES INVENTOR C/zarle; D. Wzrzzez;

lUnTTn STaTns ATFNT omen.

CHARLES D. VARNER, OF ANSONIA, CONNECTICUT.

ELECTRIC GAGE.

SPECIPICATIQN forming part of Letters Patent No. 309,114, dated December 9, 1884.

I Application filed March 10, 1884. (No model.)

To aZZ whom it may concern:

Be it known that 1, CHARLES D. \VARNER, a citizen of the United States, and resident of Ansonia, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Electric Gages, of which the following is a spccification.

My invention belongs to that class of devices by means of which the strength of can rent and the changes thereof in an electric conductor are indicated upon a properly-divided scale through the force exerted by said current in the coils of an electro-niagnet upon an armature placed in the field of force of said magnet.

The object of my invention is to afford a simple and effective gage which shall indicate at all times the strength of current in circuits where work is done by meansof one ormore electro-magnets-such as clock or tele graphic circuits-and which sh all show at once the changes that may take place in the current strength in the circuit which includes the device.

My invention consists, generally, of an electromagnet designed to be placed in series with the working electro-magnets of the circuit, having an armature held normally in a position in which it is but partially within the field of force of the magnet. The armature is connected by suitable mechanism to a pointer or hand placed in front of a divided scale, and the same is so adjusted that when no current is passing the index stands at zero, being held in that position by a spring or other extraneous force. The passage of a current tends to bring the armature into a position normal to the lines of force exerted by the magnet, which causes the index-hand to pass over the scale, indicating by its position the balance between the magnetic force and that tending to keep the hand at zero. In my invention the magnet has curved pole-pieces, the armature is a segment of a circle, and suspended by an arm or arms at the center of the segment, so that when the segment armature swings upon its center it passes close to the pole -picces, and therefore into the field of force. The armature is held at one side by a suitable spring, and the effect of the attraction of the poles upon the armature is to draw the armature into a central position opposite the said poles. Means for altering the distance between the poles and armature are provided, so that the same scale may serve for circuits operated by currents of greater or less strength. Any change in the strength of current will. be at once indicated by the change of position of the index, which follows the change of position of the armature with reference to the poles of the magnet.

The invention is especially adaptedto clockcircuits, where a series of electro-m'agnets are required to do regular work, where the strength of current is required to be as nearly constant as possible, and 'where it is desired to know at frequent intervals whether any change in the condition of the battery or the external circuit has taken place.

My invention is illustrated in the accompa nying drawings, in which Figure 1 is a front elevation of the instrument, showing case, dial, and index. Fig. 2 is a front elevation with the case and dial removed. Fig. 3 is a rear elevation with the back portion of the case partly removed, and Fig. 4 is a vertical transverse section of the instrument.

In the drawings, A represents the case of the instrument; B, the dial; C, thcindex-hand. The dial is represented as graduated from 0 to but any arbitrary or other method of division may be adopted. The index-hand is mounted upon a central arbor, c, and is balanced by the extension and weight 0 The instrument has front and back frames, D and D, fastened together by the rods (1 d d d", between which the electro-magnet E is placed. Curved pole-pieces E E are attached to the cores. Above the magnet is suspended the armature F, formed into the segment of a circle, having the arms f f, and turning at the center of the circle upon the arbor f which has bearings in the front and back frame plates of the instrument. The armature is balanced by the extension f and. weight f The curved piece D is a portion of the front frame of the instrument, and attached to this is the piece D, projecting in front of the piece D The pieces D and D are pierced for the bearings of the arbor c,which carries the index. The

spiral spring 8 is attached at one end to the arbor c, and at the other end to the back side Back of the spring 8, and

of the piece 1)".

fixed on the arbor c, is a small cog-wheel. or pinion, c. This pinion c, it will be seen, 1s in front of the front plate, and it engages with" ture are equal segments and correspond inposition to each other. The spring 8 is. so adjusted as to have a tendency to turn the arbor c, and therefore the pinion c, andthus to hold" the segment 9 and the armature F to one side.

The pin 6 actsas a stop to the segment gwhen it and the armature have reached an extreme position at one side of the magnet E. In this position the cog-wheel c is in engagement with the cogs at the end of the segment 9, and the end of the armature is slightly past the central point of the coils. The relative positions of-the magnet and armature and of the armature and segment 9 may be varied without departing from the principle of the invention.=WVl1en the armature and segment are in-their extreme position at one side of the magnet,-the index is set at zero. The terminal wires of the electro-magnet E are connected with-thebinding-posts l? P on the-outside of thecase, and the instrument may thus be connected in circuit. when an electric current is passing through the coils of the magnet the armature is drawn away from its position at one side of the coils and will move towarda central positionthat is, a position in which the middle of the armature is opposite the point m, centrally between the two coils-and if theinstrument is so adjusted that the armature will reach the central position only when under the influence of the strongest current which may be used upon the line, then all strengths of current from such greatest strength to zero can be indicated by the intermediate positions of the armature and the index. The electro-magn'et is movable between the front and back frame pieces of the instrument.

In Fig. 3 is shown the means for holding and moving the coils, so as to vary the distance between the pole-pieces and the armature. The back plate of the frame is shown at D. The piece H is bent at right angles, one end being attached to the yoke of the electro-magnet, and the other end, as shown, extends parallel and close to the piece D of the frame-plate. The piece H has elongated holes h h, through which pass the screws k.

These screws pass through the washers ZZ,'

' against the edge of the cam M. The cam is fixed upon the arbor m, which has bearings in the frame-plate D and in the cross-piece D, which is attached to the plate D at each end by screws (2 d It is evident that.

now, that by turning the arbor m, and therefore the'cam M, the piece H will be moved. a'n'd'thereby the magnet. Thus, if the parts are in the position shown in Fig. 3, the end of the piece Zr rests against theedge of the cam at a point something more than a quadrant from the point m", which is nearest the center. WVhen the cam is in position so that the end of the extension h rests against. the. point m it is evident that the pole-piece will be. nearest the armature. When the cam is turned so that the end of extension h rests against the point m at the end of the largest diameter of the cam, then the magnet is held at its farthest distance from the armature. It is easy,- therefore, to adjust the distance of the pole-pieces mature is indicated by the index I,i-which is.

fixed upon the arbor m, and which passes over a scale, T, upon the outside of theback plate of the instrument, the index standing at Lwhen the pole-pieces are nearest the'a'rmatu'rethat is, when the end of h rests against the point mand it: stands nearly atthe samemark when the'cam is turned so that the end of h rests against the point m the index having passed around the scale, and the pole-pieces are attheir farthest distance from the armature. In practice thedistance of fthepoles and armature is adj ustedfor the strength of current in the circuit in which the instrument is to be placed by turning the :index and cam until, I

when the circuit-c'onnections are made,-the i11- dex on thez'front dial stands at a convenient point-say 30thus giving a sufficient range on each side for indicating any changes that may take place. Anything which then affects the efficiency of the current for the work it is doing may be immediately sought out and remedied.

- I claim as my invention- 1. The combination, substantially as here inbefore set forth, of an electro-magnet, curved pol e-pieces to said magnet, an armature formed into the segment of a circle, said armature being suspended at its center of curvature, a counter-balance or equivalent device for hold ing said armature away from the center of the field of force of said magnet, an index or inbefore set forth, of an electro-n1agnet,=its ar- 1 mature, a counter-balance or equivalent,means for holding said armature away from the position where said magnet will exert upon said armature its greatest force, an index or pointer, and mechanical connections between said index and the armature for moving said index correlatively with the movements of said armature to or away from said position of greatest magnetic force, an adjustable frame carrying the electro-magnet, whereby the distance between said armature and the poles of said magnet may be varied.

3. The combination, substantially as hereinbefore set forth, of an electro-magnet, curved pole-pieces to said magnet, an armature forming the segment of a circle and suspended at the center of curvature of said segment, an index or pointer mechanically connected with the axis of said armature, whereby said index is adapted to move correlatively with said armature into and away from a central position with reference to said pole-pieces, and a divided scale before which said index moves.

4. The combination, substantially as hereinbefore set forth, of an electro-magnet, its armature, a spring or equivalent device for holding said armature away from a central position with reference to the lines of force of said magnet, an index or pointer, and mechanical the index 0.

6. The combination, substantially as hereinbefore set forth, of the magnet E, the polepieces E, the curved armature F, the segment 9, the pinion c, the spring .9, the index 0, the dial B, the piece H, to which said magnet is attached, the cam M, the springs N, the index I, and scale T.

In testimony whereof I have hereunto subscribed my name this 6th day of March, A. D. 1884.

CHARLES D. VARN ER.

"Wi tn esses:

J AS. B. KEENE, JOHN D. BALLOU. 

